Exam 8: Vitamins Required for Calcified Structures

Follicular hyperkeratosis, in which the skin is thickened, dry, and wrinkled, is preceded by hypervitaminosis A. The keratinization of this disorder can also affect the oral mucosa and the respiratory and gastrointestinal tracts.

Toxicity from excessive intake of vitamin A food sources is common and results in hypercarotenemia. This condition is initially manifested by yellowing of the skin on upper chest and inner forearms.

Oily fish are considered excellent sources of vitamin D. Each of the following is an oily fish except one. Which one is the exception?

Supplementing dietary intake of beta-carotene is advised for patients with leukoplakia who smoke because research documents that exogenous beta-carotene protects lung tissues from dangers of smoking.

Hypercarotenemia may be distinguished from jaundice because the sclera of the eye retains its normal white color in hypercarotenemia.

Vitamin A can be stored in the liver for at least:

International units (IU) is the designation used to measure and recommend vitamin A levels because it better represents the absorption rates in humans than retinol activity equivalent (REA).

Each of the following is true of vitamin D except one. Which one is the exception?

Which of the following nutrients acts most like a hormone?

Each of the following is true of water-soluble vitamins except one. Which one is the exception?

Osteoporosis is characterized by fragile bones and is associated with increased incidence of bone fractures. Current research indicates that it is caused by a calcium deficiency, but that the fat-soluble vitamins play major role.

Each of the following is true of retinoic acid except one. Which one is the exception?

Rickets results in shortened bones because the epiphyses of bones do form earlier than normal.

When rickets occurs, the alveolar bone is affected similar to other bones in the body. The trabeculae of the alveolar bone also weaken.

In older patients, vitamin D deficiency frequently results in falls because this deficiency is associated with muscle weakness.

Each of the following is true of xerophthalmia except one. Which one is the exception?

Fat-soluble vitamins are fairly stable when heated, as in cooking. In contrast to water-soluble vitamins, fat soluble-vitamins contain nitrogen.

Large amounts of vitamin A supplements can exceed the storage capacity of the kidneys. When present in high concentrations, unbound vitamin A causes damage to cell nuclei, especially in the white blood cells and lysosomes.

Rickets is no longer prevalent in the United States because increased breastfeeding provides ample vitamin D reserves.

Each of the following is a fat-soluble vitamin except one. Which one is the exception?